Conceptual Design Stage “It has been estimated that at least 80 percent of a vehicle’s life- cycle cost is locked in by the concept that is chosen.” NASA/TP In a similar manner, all benefits are locked in… Conceptual Design The conceptual design sets the theoretical limits. The conceptual design has the least real-world losses quantified. Therefore, there MUST be significant inherent advantages to avoid erosion of all the benefits. “One cannot figure to add margin and be assured an advantage over the existing concept, if there is no inherent, and thus untouchable, major growth factor.”

The 3 Categories of Systems Engineering The Good The Bad & The Ugly

Solar Thermal Ultra-Sail Flywheels Tethered Auto-gyro SOLEX Distributed Engine Components Many Goals, Missions, & Hard Choices

Humor - Laugh Systems Engineering is a little like this:

The Good

The Bad

The Ugly

Concluding Remarks Systems Engineering Rules 1.Identify inherent, and thus untouchable, advantages at the preliminary design stage. 2.Systems Engineering is about hard trade offs - so “pick your poison” 3.Systems Engineering is not a mass spreadsheet or individual selection of piece parts to be strung together. 4.Engineer reliability, safety, and redundancy at each level & optimize at the subcomponent level. 5.Redundancy should be a different design, approach, or system level. 6.Easily changed components are critical to the system’s total optimization! 7.You can’t system engineer physics you don’t understand. 8.System Engineering requires reasonable mass margin expectations. 9.Keep your eyes on the goal you want to achieve; being extra vigilant if that goal is simply “reduce cost”. 10.The application must fit the purpose and the subsystems must fit the design, since a mismatch is often disastrous on the system’s performance. And remember… “A man’s got to know his limitations.” Dirty Harry, Magnum Force  Don’t be critical, but try to find the good or utility in everyone's ideas and research.  Beauty is in the eye of the beholder; if it works it becomes elegant, otherwise it remains an ugly dog.